Aromatic amide groups-containing diamines and polymers in which these diamines are incorporated

ABSTRACT

There is provided a new class of diamines of the formula &lt;CHEM&gt; wherein X = NH or O, and R represents a divalent, substituted or unsubstituted organic group having at the most 20 carbon atoms. The diamines, wherein X has the meaning of an O-atom, may be converted with diacids, diacid dichlorides, aromatic carboxylic acid anhydrides or diisocyanates into poly(esteraramid) amides, poly(esteraramid) imides, or poly(esteraramid) urea or, when X stands for an -NH-group, into poly(amidaramid) amides, poly(amidaramid) imides, or poly(amidaramid) urea. The wholly or largely aromatic polyamides, polyurea or polyimides are of an iterative structure. They can be melt-processed into shaped objects displaying a very good resistance to high temperatures, particularly when use is made of diamines having meta-substituted amide groups or diamines of a non-aromatic structure for the -XRX- group, or of a non-aromatic structure of the diacids, diacid dichlorides, aromatic carboxylic acid anhydrides or diisocyanates to be linked to the diamines. By altering the chemical structure of the diamines on the one hand and the diamine-linkable bifunctional compounds on the other, both the melting performance and the level of crystallinity of the end product may be influenced.

The invention relates to diamines of the formula ##STR2## wherein X=NHor O, and R represents a divalent, substituted or unsubstituted organicgroup having at the most 20 carbon atoms. The invention also relates toa process for the preparation of these diamines, as well aspoly(esteraramid)amides, poly(esteraramide)imides,poly(esteraramid)urea, poly(amidaramid)amides, poly(amidaramid)imides,and poly(amidaramid)urea incorporating these diamines.

Polymers having aromatic amide groups are generally known. They are usedprimarily because of their great strength combined with a very goodresistance to high temperatures. A major disadvantage of these polymersis that they are generally not suited to be melt processed.

Therefore, U.S. Pat. No. 3,926,923 proposes the use of copolymers withpart of the aromatic amide groups-containing segments being replacedwith groups of an aliphatic structure. However, a major disadvantage ofthese copolymers is their random structure, which is due to "at random"copolymerization. In general, this results in polymers of which thepreparation is difficult to reproduce.

Finally, it should be noted that the preparation of an aromatic amidegroups-containing diamine as precursor in the preparation of aromaticamide groups-containing polymers was in itself already known from U.S.Pat. No. 3,049,518. The preparation of the only diamine describedtherein, viz. N,N'-bis(3-aminophenyl)-isophthalamide, is however, foundto be attended with the formation of a high percentage of by-products,in particular low-molecular weight polymer.

The use of diamines of the above structure will result in obtainingwholly or largely aromatic polyamides, polyurea or polyimides of aniterative structure, which can be melt-processed into shaped objectsdisplaying a very good resistance to high temperatures, particularlywhen use is made of diamines having meta-substituted amide groups ordiamines of a non-aromatic structure for the --XRX-- group, or of anon-aromatic structure of the diacids, diacid dichlorides, aromaticcarboxylic acid anhydrides or diisocyanates to be linked to thediamines. By altering the chemical structure of the diamines on the onehand and the diamine-linkable bifunctional compounds on the other, boththe melting performance and the level of crystallinity of the endproduct may be influenced.

Apart from said homopolymers, copolymers may of course be prepared inwhich the diamines according to the invention are replaced in part withother diamines of an aliphatic or aromatic structure, or copolymers maybe prepared from mixtures of diacids, diacid dichlorides, aromaticcarboxylic acid anhydrides or diisocyanates. Alternatively, copolymersmay be obtained by using a mixture of diamines according to theinvention.

It has been shown in actual practice that polymers with highlysatisfactory properties may be obtained by using a diamine of saidformula with the R group representing an alkylene group having 2-10carbon atoms. As examples of suitable alkylene groups may be mentionedethylene, butylene and hexamethylene as well as such branched-structurealkylene groups as neopentylene, isobutylene, and isooctylene or2-ethylhexylene.

Alternatively, R may represent a cycloaliphatic structure such ascyclohexylene or 1,4-dimethylene cyclohexylene or it may represent anaromatic group such as an m- or p-phenylene group.

If in the diamine formula all amide groups are in the p-position, and Ris to stand for a p-phenylene group and X for an --NH--group, and if theresulting diamine is polymerized with terephthaloyl dichloride, theresulting product will be the non-melting poly-p-phenyleneterephthalamide, which is suited only to be processed into pulp or intothe well-known polyaramid fibres. If, however, all amide groups are inthe m-position, with R standing for an m-phenylene group and X for an--NH--group, then polymerization with isophthaloyl dichloride willresult in poly-m-phenylene isophthaloyl amide, which will not melteither without thermal decomposition and which is used in theelectrotechnical industry on account of its favourable dielectricproperties combined with a very good resistance to high temperatures.

Naturally, the advantages of the present invention will only fullymanifest themselves when a polymer processable via the melt is obtainedby a certain selection from the group --XRX--, m- or p-substitution andfrom the diacid, diacid dichloride, diisocyanate, or carboxylic acidanhydride used in polymerization.

Polymers of superior properties may be obtained from a diamine havingthe above formula, wherein R represents the group ##STR3## wherein Y hasthe meaning of a linear or branched alkylene group having 1-4 carbonatoms, --O--, --SO₂ --, ##STR4##

Polymers having very good properties may also be obtained by making useof a diamine of said formula wherein R represents the group ##STR5##wherein R₁ and R₂ may be the same or different and represent a branchedor unbranched alkylidene group having 2 to 5 carbon atoms. Preference isthen given to a polymer derived from a diamine in which R₁ and R₂ bothhave the meaning of an ethylene group and X represents an O-atom.

The invention also provides a process for the preparation of diaminesaccording to the above formula, in which process use is made ofprocedures known in themselves from chemical technology for convertingthe acid chloride of a half ester of terephthalic acid or isophthalicacid with m- or p-nitroaniline, the resulting reaction product istrans-esterified with a bifunctional alcohol of the fiormula HOROH, orconverted therewith or with a diamine of the formula H₂ NRNH₂, afterhydrolysis and chlorination, the resulting dinitro compound is reducedwith hydrogen to the corresponding diamine, which diamine is thenisolated.

In actual practice the procedure is as follows: first the half ester isprepared from: dimethyl isophthalate or dimethyl terephthalate bycontrolled saponification with a solution of KOH in methanol. Theresulting precipitate is dissolved in hot water subsequent tofiltration, followed by acidification, filtration and recrystallizationto obtain the corresponding half ester in the pure state. The half esterthus prepared is next converted into the correspondingcarbomethoxybenzoyl chloride using an excess of thionyl chloride.

For the preparation of the nitrobenzanilide ester therefrom a solutionof a nitroaniline in dimethylacetamide is converted in the presence ofpyridine as acid binder with a stoichiometric amount of 3- or4-carbomethoxybenzoyl chloride in dimethylacetamide. Subsequent topouring into ice water, filtering, and washing with water and methanol,and subsequent to drying a product is obtained which is converted with adivalent alcohol and/or amine into the corresponding dinitro compound.The conversion by transesterification may be carried out for instance byboiling with refluxing in the presence of both the alcohol and a solventsuch as o-dichlorobenzene and of an organic titanium catalyst such astetraisopropyl orthotitanate. Conversion with an alcohol or a diaminemay also be effected by chlorinating the resulting acid--optionally insitu--after hydrolysis of the ester, followed by the addition of thediol or the diamine in dimethylacetamide in the presence of an acidacceptor such as pyridine. On conclusion of the reaction the reactionmixture is poured into ice water, the precipitate is washed thoroughlywith water and methanol, and dried.

Under certain conditions, especially when of the group --XRX-- X has themeaning of ##STR6## and R of alkylene, the process above-discussed doesnot always have the desired result.

For that reason the invention provides an alternative process, wherebywith methods known in themselves from chemical technology the acidchloride of a half ester of terephthalic acid or isophthalic acid isconverted with a bifunctional alcohol of the formula HOROH or with adiamine of the formula H₂ NRNH₂ in the presence of an acid binder, theresulting diester is hydrolyzed to the corresponding diacid, and thediacid is converted with m- or p-nitroaniline, after which the resultingdinitro compound is reduced with hydrogen to the corresponding diamine,which diamine is then isolated. The conversion with m- or p-nitroanilineis preferably carried out in the presence of a solution of lithiumchloride in a mixture of N-methyl pyrrolidone, pyridine and triphenylphosphite.

The resulting dinitro compound is finally subjected to a catalytichydrogenation process to obtain a diamine having the structure of theabove formula. As examples of suitable solvents for the hydrogenationreaction may be mentioned dimethylacetamide, hexamethyl phosphorictriamide or N-methyl pyrrolidone. Further reaction conditions such ashydrogen pressure, reaction temperature and the total amount of hydrogento be added should be carefully controlled so as to avoidoverhydrogenation. On conclusion of the hydrogenation reaction thereaction product is separated from the catalyst suspension by filtrationand purified by recrystallization from dimethylacetamide. The resultingdiamines, wherein X has the meaning of an O-atom, may be used in thepreparation of poly(esteraramid)amides, poly(esteraramid)imides, orpoly(esteraramide)urea or, when X stands for an --NH--group, ofpoly(amidaramid)amides, poly(amidaramid)imides, or poly(amidaramid)urea.

The preparation of poly(esteraramid)amides or poly(amidaramid)amidesaccording to the invention may be carried out analogous to the methoddescribed for the well-known polyaramids in Kirk-Othmer, Encyclopedia ofChemical Technology, 3rd Ed. Vol. 3 (1978), pp. 229-237.

In the preparation on a laboratory scale advantageous use may be made ofa method described by Yamazaki et al. in the Journal of Pol. Sci., Vol.13 (1975), pp. 1373-1380. In the case of preparation on an industrialscale preference is generally given to interfacial polymerization orpolymerization from the solution.

In interfacial polymerization the acid is dissolved or dispersed in aninert, water-immiscible organic solvent, preferably a swelling agent forthe polymer, and the diamine is dissolved or dispersed with a protonacceptor in the aqueous phase. Next, the system is preferably quicklystirred, after which the polymer is collected and dried.

For polymerization in solution preference is given to polycondensationof diacid dichlorides and diamines in amide groups-containing solvents.In the case of solvent polymerization the polymerization medium acts asa solvent for at least one of the reaction components and as a solventor swelling agent for the polymer. In order that the reaction may be asnearly complete as possible an acid acceptor, usually a tertiary amine,is used. As suitable solvents may be mentioned dimethyl acetamide,N-methyl pyrrolidone and tetramethylurea. To enhance the dissolvingpower use is generally made of inorganic salts such as lithium chlorideand calcium chloride.

As diacid dichlorides generally suitable for the preparation ofpoly(esteraramid)amides or poly(amidaramid)amides may be mentionedcompounds of the formula A--Q--A, whereinA has the meaning of a carbonylchloride group and Q represents a divalent organic group with 2-40carbon atoms. Generally, compounds are preferred wherein Q stands for anm- or p-phenylene group, an alkylene group having 2-8 carbon atoms or acyclohexylene or dimethylene cyclohexylene group. As examples of diaciddichlorides which may be reacted with the diamines according to thepresent invention to form the aforementioned compounds may be mentionedadipoyl dichloride, sebacoyl dichloride, cyclohexane-1,4-dicarbonyldichloride, cyclobutane-1,3-dicarbonyl dichloride, isophthaloyldichloride, bibenzoyl dichloride, 2,6-naphthalene dicarbonyl dichloride,1,1,3-trimethyl-3-phenylindane-4',5-dicarbonyl dichloride, oxaloyldichloride, fumaroyl dichloride and diacid dichlorides of the formula##STR7## wherein R has the same meaning as given in the first formula.

The preparation of poly(esteraramid)imides and poly(amidaramid)imidesmay be carried out by converting the diamines in question with anaromatic carboxylic acid anhydride having 9 to 24 carbon atoms to form apoly(esteraramid)amide and poly(amidaramid)amide, respectively, followedby heating at a temperature in the range of 150° to 300° C. to form therespective imides.

In the conversion use is preferably made of an aprotic solvent such asdimethylacetamide.

According to the invention preference is generally given to a method ofpreparation in which for the carboxylic acid anhydride is usedtrimellitic acid anhydride, pyromellitic acid dianhydride, and inparticular benzophenone tetracarboxylic acid dianhydride. Finally, thediamines according to the invention may be converted with an equivalentamount of maleic acid anhydride to form the corresponding diimides. Intheir turn these diimides may be converted with an equivalent amount ofdiamine while forming the corresponding polyimides.

An advantage of the latter process is the absence of volatileby-products.

Preparation of poly(esteraramid)urea and poly(amidaramid)urea may takeplace by conversion of the diamines with a diisocyanate of the formulaOCN--Q--NCO, wherein Q stands for a divalent organic group having 2-20carbon atoms. Preferably use is made in the conversion of a solvent suchas N-methyl pyrrolidone. According to the invention a method ofpreparation is commonly preferred in which use is made of a diisocyanateof the above formula wherein Q represents a divalent aliphatic,alicyclic or aromatic group.

As suitable diisocyanates for conversion according to the presentinvention into said poly(esteraramid)urea and poly(amidaramid)urea maybe mentioned: hexamethylene diisocyanate, dimethyl hexamethylenediisocyanate, trimethyl hexamethylene diisocyanate, m-xylylenediisocyanate, and tetramethylene diisocyanate.

When Q stands for an aromatic group, this group may be substituted withhalogen or a lower alkyl or alkoxy group. Examples include:1-chloro-2,4-phenylene diisocyanate, 2,4-toluene diisocyanate, a mixtureof 2,4- and 1,6-toluene diisocyanate, tetramethylphenylene diisocyanate,diphenylmethane-4,4'-diisocyanate, m-phenylene diisocyanate, p-phenylenediisocyanate, diphenyl-4,4'-diisocyanate,biphenylmethane-4,4'-diisocyanate, biphenyldimethylmethane-4,4'-diisocyanate, benzophenone-4,4'-diisocyanate,biphenyl ether diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate andbenzofuran-2,7-diisocyanate.

As examples of diisocyanates having an alicyclic group may be mentioned:isophorone diisocyanate, dicyclohexylmethane diisocyanate and1,4-cyclohexane diisocyanate.

In general, the polymers according to the invention may bemelt-processed into shaped articles by prior art methods used forpolymers resistant to high temperatures. In this way also very strongfilms and fibres may be made. Alternatively, fibres may be obtained bythe wet spinning process known to be used for wholly aromaticpolyamides.

The invention will be further described in, but not limited by thefollowing examples.

EXAMPLE I Preparation of the monomethyl ester of terephthalic acid

In a 3-liter 3-necked flask, fitted with a mechanical stirrer, a refluxcondenser and a dropping funnel were 194 g (1 mole) of dimethylterephthalate (DMT) in 2 liters of methanol, with the DMT not fullydissolving in the methanol. Over a period of 50 minutes there were added64.2 g (1 mole) of KOH (88%) dissolved in 300 ml of methanol. A whiteprecipitate was formed. After all the ingredients had been added,stirring was continued for another 90 minutes. After cooling to 30°-35°C. the precipitate was isolated by filtration and dissolved in hot waterof 90° C. Following hot filtration the solution was acidified with 4NHCl, leading to the formation of a white precipitate. After filtration,recrystallization, and drying at 60° C. in vacuo 116.5 g of the presentproduct were obtained in a yield of 65%. The melting point was219.3°-219.9° C.

EXAMPLE II Preparation of the monomethyl ester of isophthalic acid

The method of preparation described in Example I was repeated, exceptthat use was made of dimethyl isophthalate (DMI) in an amount of 48.5 g(0.25 moles) in 150 ml of methanol. After stirring and heating to 35° C.the DMI completely dissolves. To this solution there was added over aperiod of 30 minutes at 35° C. a solution of 16 g (0.25 moles) of KOH(88%) in 80 ml of methanol. After 90 minutes' stirring and cooling to 8°C. a precipitate was formed, which continued to grow on heating to 40°C. Following filtration and washing with diethyl ether (to removenon-converted DMI) a white cake was obtained. After dissolving in waterand acidification with 4NHCl 34.7 g of monomethyl ester were obtained ina yield of 75%. The melting point of the monomethyl ester of isophthalicacid was 186°-191° C.

EXAMPLE III Preparation of 4-carbomethoxybenzoyl chloride

Into a 1-liter 3-necked flask fitted with a mechanical stirrer, a refluxcondenser and a thermometer were introduced 540 g (3 moles) of themonomethyl ester of terephthalic acid and 500 g (4.2 moles) of thionylchloride. After heating to 80° C. a clear solution of4-carbomethoxybenzoyl chloride and an excess of thionyl chloride wereobtained after 6 hours. Following the removal of the thionyl chloridethe residue was distilled in vacuo. Obtained were 586 g of said productin a yield of 98%. The boiling point was 140° C. at 1.47 kPa.

EXAMPLE IV Preparation of 3-carbomethoxybenzoyl chloride

Into a 250 ml 3-necked flask fitted with a magnetic stirrer, a refluxcondenser and a thermometer were introduced 61.0 g of the monomethylester of isophthalic acid (0.33 moles) and 64 g of thionyl chloride(0.54 moles). After heating to 75° C. a clear solution was obtainedafter 1 hour. Obtained were 64.0 g of 3-carbomethoxybenzoyl chloride,which corresponds to a yield of 97%.

EXAMPLE V Preparation of methyl-3-(p-nitrophenylcarbamoyl)benzoate

In a 1-liter 3-necked flask fitted with an inlet tube for nitrogen, amagnetic stirrer, a dropping funnel and a thermometer there wereintroduced 76 g (0.5 moles) of p-nitroaniline in 600 ml ofdimethylacetamide and 80 ml of pyridine. (Both solvents had previouslybeen dried over a molecular sieve 3A). Over a period of 45 minutes 99.2g (0.5 moles) of 3-carbomethoxybenzoyl chloride in 100 ml ofdimethylacetamide were added with stirring and cooling, care being takenthat the temperature did not rise to above 15° C. In the process ayellow precipitate was formed. After all the ingredients had been added,stirring was continued for 1 more hour at 20° C. The reaction mixturewas poured into 2 l of ice water, filtered, washed 6 times with waterand finally with methanol. After drying at 70° C. and a pressure of 133Pa 146 g of the envisaged product were obtained in a yield of 97%. Themelting point was 206°-207.6° C. In an analogous manner there wereprepared:

    ______________________________________                                                              Melting point °C.                                ______________________________________                                        methyl-3-(m-nitrophenylcarbamoyl) benzoate                                                            160.0-162.7                                           methyl-4-(m-nitrophenylcarbamoyl) benzoate                                                            179.8-181.3                                           methyl-4-(p-nitrophenylcarbamoyl) benzoate                                                            231.2-231.5                                           ______________________________________                                    

EXAMPLE VI Preparation ofO,O'-bis[3(m-nitrophenylcarbamoyl)benzoyl]hexamethylene glycol

Into a 500 ml 3-necked flask fitted with a magnetic stirrer, an inlettube for N₂, a thermometer and a Soxhlet apparatus with reflux condenserwere introduced 30 g of methyl-3-(m-nitrophenylcarbamoyl)benzoate (0.1mole), 6 g (0.05 moles) of hexane diol-1,6, 300 ml of dryo-dichlorobenzene and 3 drops of tetraisopropylorthotitanate (TIPOT).The reaction mixture was stirred for 3 hours at 170°-180° C. Themethanol released was bound by molecular sieves 4Å in the Soxhletapparatus. After cooling the precipitate was isolated by filtration,washed with methanol and pentane and then dried for 24 hours at 70° C.and 65 Pa.

Obtained were 29.9 g of the envisaged product in a yield of 91%. Themelting point was 214°-217.0° C.

In an analogous manner there were prepared:

O,O'-bis[4(p-nitrophenylcarbamoyl)benzoyl]hexamethylene glycol with amelting point of 264.1°-266.3° C.

O,O'-bis[4(m-nitrophenylcarbamoyl)benzoyl]hexamethylene glycol with amelting point of 220.3°-220.8° C.

O,O'-bis[3(p-nitrophenylcarbamoyl)benzoyl]hexamethylene glycol with amelting point of 187.0°-191.0° C.

EXAMPLE VII Preparation ofO,O'-bis[4(m-aminophenylcarbamoyl)benzoyl]hexamethylene glycol.sup.(A)according to the invention

In a 250 ml Hofer autoclave were introduced 30 g ofO,O'-bis[4(m-nitrophenylcarbamoyl)benzoyl]hexamethylene glycol in 150 mlof dimethylacetamide together with 3.0 g of Raney Ni suspension inwater. The reduction was carried out at a temperature of between 70° and100° C. and an initial hydrogen pressure of 4000 KPa. After 2 hours thereduction was complete and the reaction mixture--after filtration of theRaney Ni--was poured into 1.5 l of ice water. A pale pink precipitatewas formed which, after recrystallization from n-butanol, resulted in 25g of the envisaged compound in a yield of 91%. The melting point wasfound to be 220.3°-220.8° C. In an analogous manner there were prepared:

O,O'-bis[3(m-aminophenylcarbamoyl)benzoyl]hexamethylene glycol.sup.(B)with a melting point of 167°-170° C.

O,O'-bis[4(p-aminophenylcarbamoyl)benzoyl]hexamethylene glycol.sup.(C)with a melting point of 264.1°-266.3° C.

O,O'-bis[3(p-aminoiphenylcarbamoyl)benzoyl]hexamethylene glycol.sup.(D)with a melting point of 187°-191° C.

EXAMPLE VIII Preparation of

O,O'-bis[3(p-aminophenylcarbamoyl)benzoyl]ethylene glycol.sup.(E),

O,O'-bis[4(m-aminophenylcarbamoyl)benzoyl]neopentyl glycol.sup.(G), and

O,O'-bis[3(m-aminophenylcarbamoyl)benzoyl]bisphenol-A.sup.(F).

For the preparation of these diamines were usedmethyl-3-(p-nitrophenylcarbamoyl)benzoate,methyl-4(m-nitrophenylcarbamoyl)benzoate, andmethyl-3-(m-nitrophenylcarbamoyl)benzoate, respectively, the preparationof which is given in Example V. After saponification of the respectivemethyl esters with 2 moles of base per mole of ester, acidification, andchlorination of the carboxyl group with thionyl chloride, the respectiveacid chlorides were converted with ethylene glycol, neopentyl glycol andbisphenol A, respectively, into the corresponding dinitro compounds.After reduction with hydrogen the envisaged compounds were obtained.

EXAMPLE IX a. Preparation of 4-(m-nitrophenylcarbamoyl)benzoic acid

Into a 10 l flask fitted with an inlet tube for nitrogen, a mechanicalstirrer, a dropping funnel, and a thermometer were introduced at roomtemperature 500 g (1.66 moles) ofmethyl-4-(m-nitrophenylcarbamoyl)benzoate in 4 l of dimethylacetamide.To the yellow solution there was added dropwise with stirring andcooling a solution of 231 g (85%) of KOH (3.5 moles) in 1 l of methanol.Subsequently, the orange solution was stirred for another hour at 60° C.Next, the reaction mixture was acidified with a dilute solution ofhydrochloric acid. The resulting precipitate was filtered, washed withwater, and dried in vacuo. Obtained were 457 g of the envisaged productwith a melting point of 319° C. (DSC) in a yield of 96%.

b. Preparation ofN,N'-bis[4-(m-nitrophenylcarbamoyl)benzoyl]oxydianiline

Into a 6 l, 3-necked flask fitted with an inlet tube for nitrogen, amechanical stirrer, a thermometer, a reflux condenser, and a droppingfunnel were introduced 286 g (1 mole) of4-(m-nitrophenylcarbamoyl)benzoic acid and 100 g of oxydianilinetogether with 311 g of triphenyl phosphite and 1.6 l of Yamazaki reagent(a solution of 1.4 l of N-methyl pyrrolidone, 1.07 l of pyridine, and100 g of lithium chloride).

The reaction mixture was slowly heated to 83° C. and kept at thistemperature for 2 hours. After cooling to room temperature the reactionmixture was slowly diluted with methanol until a volume of 5 l wasobtained. The resulting precipitate was filtered, washed thoroughly withmethanol, and dried in vacuo.

Obtained were 345 g of the envisaged product with a melting point of332° C. (DSC) in a yield of 96%.

c. Preparation of N,N'-bis[4-(m-nitrophenylcarbamoyl)benzoyl]ethylenediamine

Into a 3 l 3-necked flask fitted with an inlet tube for nitrogen, amechanical stirrer, a reflux condenser, and a dropping funnel wereintroduced 80 g (0.21 moles) of N,N'-bis(p-carbomethoxybenzoyl)ethylenediamine (obtained by reacting 1 equivalent of ethylene diamine with 2equivalents of p-carbomethoxybenzoyl chloride) with 400 ml ofdimethylacetamide and 400 ml of water. To this was added dropwise asolution of 30 g (85%) of KOH in 500 ml of methanol. The reactionmixture was then stirred for 2.5 hours at a temperature of 70° C. Aftercooling to room temperature dilute hydrochloric acid was added. Theprecipitate was filtered, washed several times with water, and dried for24 hours at 80° C. and a pressure of 1.6 kPa, and subsequently driedagain at 90° C. and a pressure of 53 Pa.

Obtained were 74 g of diacid with a melting point of 352° C. in a yieldof 99%.

Of this diacid 73.6 g (0.206 moles) were introduced with 58.0 g (0.42moles) of m-nitroaniline, 160 g of triphenyl phosphite, and 800 ml ofYamazaki reagent (a solution of 1.4 l N-methyl pyrrolidone, 1.07 l ofpyridine, and 100 g of lithium chloride) into a 3 l 3-necked flaskfitted with an inlet tube for nitrogen, a mechanical stirrer, a refluxcondenser, and a dropping funnel. Over a period of 75 minutes thetemperature was slowly increased to 85° C. Next, stirring took place fora further 3 hours. After cooling to room temperature there were slowlyadded to the mixture 1200 ml of methanol. The resulting precipitate wasfiltered, washed with methanol, and dried in vacuo. Obtained were 119 g(97%) of the envisaged product with a melting point of 365° C. (DSC).

d. Preparation of N,N'-bis[4-(m-aminophenylcarbamoyl)benzoyl]ethylenediamine (K)

The preparation of this compound was carried out as indicated in ExampleVII for the preparation of compound (A).

In an analogous manner there were prepared:

N,N'-bis[4-(m-aminophenylcarbamoyl)benzoyl]propylene diamine-1,3 (L),

N,N'-bis[4-(m-aminophenylcarbamoyl)benzoyl]decamethylenediamine-1,10(M), and

N,N'-bis[4-(m-aminophenylcarbamoyl)benzoyl]oxydianiline (N).

EXAMPLE X

Preparation of a number of poly(esteraramid)amides fromO,O'-bis-[4(m-aminophenylcarbamoyl)benzoyl]hexamethylene glycol, thepreparation of which is discussed in Example VII (diamine A), and fromisophthalic acid (IFT), adipic acid (ADP),1,1,3-trimethyl-3-phenylindane-4'5-dicarboxylic acid (PIDA), 1,7-heptanedicarboxylic acid (HPC), 1,10-decane dicarboxylic acid (DCD), 5-tertiarybutyl isophthalic acid (TIFT), 2,6-naphthalenedicarboxylic acid (NAD),and terephthalic acid (TFT), respectively.

Into a 500 ml, 3-necked flask fitted with a glass stirrer, an inlet tubefor N₂, a thermometer, a reflux condenser and a dropping funnel therewere successively introduced:

29.7 g of diamine A (0.05 moles),

8.3 g of isophthalic acid (0.05 moles),

7 g of lithium chloride,

32 g of triphenyl phosphite,

100 ml of N-methyl pyrrolidone (dried on molecular sieves 3Å) and

75 ml of pyridine

Following the removal of all oxygen by the passage of nitrogen, themixture was slowly heated to 80° C., with stirring. After a reactionperiod of 4.5 hours the reaction mixture was cooled to room temperatureand subsequently 250 ml of methanol were added dropwise to the viscouspolymer solution. After several washings with methanol in a "waringblender" the polymer solution was dried in vacuo. The polymer having asrecurring unit-A-IFT-was obtained in a yield of 99% of theory. Themeasured relative viscosity, measured in an Ubbelohde viscosimeter at25° C. on a solution of 0.5 g of polymer in 100 ml of solvent consistingof dimethylacetamide (DMA) in which per liter 50 g of LiCl weredissolved, amounted to 1.87 which corresponds to η_(inh) =1.25.

The results of the remaining measurements conducted on this polymer areshown in Table I below.

The TGA and DSC (Differential Scanning Calorimetry) data given in thetable were determined in a nitrogen atmosphere at a heating rate of 10°C./minute using a Du Pont Thermal Analyser. In this table T_(g) standsfor the glass transition temperature, T_(m) for the melting point, andT_(d) for the decomposition temperature.

On repetition of the polymerization using each time one of theaforementioned diacids there were obtained polymers having the followingproperties given in the table below.

                                      TABLE I                                     __________________________________________________________________________    Polymer having                                                                        TGA loss of weight   ηrel                                         for a recurring                                                                       at temperature in °C.                                                            DSC in °C.                                                                        (0,5%)                                           unit    0%   10%  T.sub.g                                                                          T.sub.m                                                                            T.sub.d                                                                          (DMA/LiCl)                                                                           ηinh                                  __________________________________________________________________________                            325                                                                              360                                                                              1.87   1.26                                     --A--IFT--                                                                            345  385  202                                                                                360                                                                            260                                                                              330                                                                              1.97   1.36                                     --A--ADP--                                                                            320  385  154                                                                                312                                                                            235                                                                              315                                                                              1.98   1.37                                     --A--HPC--                                                                            340  --   133                                                                                250                                                    --A--DCD--                                                                            330  390  132  260                                                                              320                                                                              2.62   1.93                                      --A--TIFT--                                                                           345  385  213  -- 350                                                                              1.96   1.35                                      --A--PIDA--                                                                           360  390  225  -- 350                                                                              1.79   1.16                                      --A--NAD--                                                                            345  375  210  360                                                                              370                                                                              4.10   2.82                                      --A--TFT--                                                                            345  385  --   365                                                                              370                                                                              2.26   1.63                                      __________________________________________________________________________

EXAMPLE XI

In this example the physical properties are given of polymers obtainedby the polymerization of the diamines A through G (prepared in theexamples VII and VIII) with terephthalic acid (TFT), isophthalic acid(IFT), 1,1,3-trimethyl-3-phenylindane-4',5-dicarboxylic acid (PIDA) oradipic acid (ADP). With the exception of polymer C-TFT, in thepreparation of which acid dichloride was used, all other polymers wereprepared from the diamine and the diacid according to the method ofYamazaki et al. as described in the J. Pol. Sci. Pol. Chem. Ed. 13, 1373(1975). The results of the tests are given in the table below.

                  TABLE II                                                        ______________________________________                                        Polymer having                                                                          TGA loss of weight                                                  for a recur-                                                                            at temp in °C.                                                                        DSC in °C.                                    ring unit 0%        10%      T.sub.g                                                                              T.sub.m                                                                            T.sub.d                              ______________________________________                                        --C--TFT--                                                                              360       410                                                       --D--IFT--                                                                              335       385      192    359                                       --B--IFT--                                                                              350       385      167    298                                       --D--ADP--                                                                              300       380      180    316                                                                           340                                                                           223                                       --B--ADP--                                                                              320       360      137    261                                       --F--IFT--                                                                              325       400      223    --                                        --F--ADP--                                                                              310       360      171    --                                        --E--IFT--                                                                              325       440             307                                       --E--ADP--                                                                              320       360      168    296                                       --D--PIDA--                                                                             330       380      219    --                                        --G--IFT--                                                                              364       420      232    335  350                                  --G--PIDA--                                                                             375       445      235    --                                        --G--ADP--                                                                              320       405      180    262  330                                  ______________________________________                                    

EXAMPLE XII

In a manner analogous to the one given in Example Xpoly(amidaramid)amides were prepared from the diamines K, L, M, and N ofExample IX and the following diacids and diacid dichlorides,respectively:

terephthalic acid (TFT)

isophthalic acid (IFT)

5-tertiary butyl isophthalic acid (TIFT)

1,1,3-trimethyl-3-phenylindane-4',5-dicarboxylic acid (PIDA)

2,6-naphthalenedicarboxylic acid (NAD)

adipic acid (ADP)

1,7-heptane dicarboxylic acid (HPC)

1,10-decane dicarboxylic acid (DCD)

The results of the measurements carried out on these polymers are givenin the table below.

    ______________________________________                                                   TGA loss                                                                      of weight                                                          Polymer having                                                                           at temp. in             ηrel                                   for a recurring                                                                          °C. DSC in °C.                                                                          0,5% in                                    unit       0%     10%     T.sub.g                                                                            T.sub.m                                                                            T.sub.d                                                                            DMA/LiCl                             ______________________________________                                        --K--IFT-- 316    400     --   375  316  1.30                                 --K--TFT-- 320    414     --   --   334  1.24                                 --K--TIFT  373    410     --   --   360  1.24                                 --K--PIDA--                                                                              372    420     200  --   360  1.23                                 --K--NAD-- 337    410     275  --   --   1.31                                 --K--ADP-- 296    380     200  --   --   1.27                                 --K--HPC-- 300    382     198  325  --    1.27                                --K--DCD-- 300    380     --   325  --   1.26                                 --L--IFT   315    410     240  360  --   1.58                                 --L--TFT   335    425     200  --   345  1.53                                 --L--TIFT--                                                                              320    415     260  --   325  1.48                                 --L--PIDA--                                                                              340    420     270  --   330  1.35                                 --L--NAD-- 350    420     212  --   340  1.73                                 --L--ADP-- 300    380     200  337  --   1.47                                 --L--HPC-- 300    400     192  310  --   1.74                                 --L--DCD-- --     --      183  307  --   1.51                                 --M--IFT-- 260    390     163  --   315  1.42                                 --M--TFT-- 275    390     183  --   340  1.39                                 --M--TIFT--                                                                              300    400     198  --   350  1.38                                 --M--PIDA--                                                                              340    405     210  --   350  1.20                                 --M--NAD-- 310    392     185  315  --   1.37                                 --N--IFT-- 365    505     --   235  370  1.57                                 --N--TFT-- 360    515     --   245  --   1.51                                 --N--TIFT--                                                                              350    480     275  --   --   1.48                                 --N--PIDA--                                                                              350    480     282  --   --   1.34                                 --N--NAD-- 360    512     --   --   --   1.69                                 --N--ADP-- 315    405     --   240  300  1.49                                 --N--HPC-- 315    407     --   240  --   1.61                                 ______________________________________                                    

EXAMPLE XIII Preparation of poly(esteraramid)urea

Making use of O,O'-bis[4(m-aminophenylcarbamoyl)benzoyl]hexamethyleneglycol, the preparation of which was described in Example VII (diamineA), there were prepared with 1,4-cyclohexyl diisocyanate (CHDI),p-phenylene diisocyanate (PPDI), and 4,4'-methylene bis(phenylisocyanate) (MDI), respectively, three poly(esteraramid)urea in anitrogen atmosphere, using dimethylacetamide as solvent.

In a 500 ml, 3-necked flask fitted with a stirrer, an inlet tube for N₂,a thermometer, a reflux condenser, and a dropping funnel was a solutionof 29.7 g of diamine A (0.05 moles) in 200 ml of dimethylacetamide.

To this solution was slowly added dropwise a solution of 12.49 g (0.05moles) of 4,4'-methylene bis(phenyl isocyanate) (MDI) in 75 ml ofdimethylacetamide, with the temperature rising from 20° C. to 28° C.

On conclusion of the addition stirring was continued for another hour.Next, stirring was continued for four hours at 65° C., after which thesolution was cooled to room temperature and subsequently poured into avery well stirred solution of 2 l of methanol. A white precipitate wasformed which, after filtration and drying (over a period of 8 hours at95° C./50 Pa), resulted in a yield of 42.8 g of the polyurea.

On repetition of the polymerization with PPDI and CHDI polymers wereobtained having the following properties given in the table below.

                  TABLE IV                                                        ______________________________________                                        Polymer having                                                                          TGA loss of weight      ηrel                                    for a recurring                                                                         at temp. in °C.                                                                      DSC in °C.                                                                       0,5%                                        unit      0%       10%      T.sub.g                                                                            T.sub.d                                                                            DMA/LiCl                                ______________________________________                                        --A--MDI--                                                                              255      310      --   255  1.26                                    --A--PPDI--                                                                             255      310      --   255  1.38                                    --A--CHDI--                                                                             260      325      125  255  1.12                                    ______________________________________                                    

EXAMPLE XIV Preparation of poly(esteraramid)imide

To a solution of 14.85 g (0.025 moles) ofO,O'-bis[4(m-aminophenylcarbamoyl]benzoyl)hexamethylene glycol, thepreparation of which is described in Example VII (diamine A), in 100 mlof dimethylacetamide (dried on Molecular Sieves 3Å) were added withstirring in an N₂ atmosphere over a period of 3 minutes, use being madeof a powder metering apparatus, 8.05 g (0.025 moles) of benzophenonedianhydride. Following after flushing with 50 ml of dimethylacetamidethe temperature slowly rose to 32° C., with the viscosity of the clear,light yellow solution increasing rapidly. After 2 hours' stirring atroom temperature a relative viscosity of 1.78 was measured on a 1.1 wt.%solution in dimethylacetamide at 25° C., which corresponds to η_(inh)=0.52. Of the polyamic acid solution 21 ml was poured onto a glass plateof 540 cm². After drying for 90 minutes in open air at 65° C. a lightyellow film was obtained. This film was slowly heated in aforced-draught furnace over a period of 4 hours from 60° C. to 215° C.The resulting polyimide film was yellow, flexible, and transparent. Forthe glass transition temperature a value of 210° C. was measured; thedecomposition temperature was found to be 325° C.

We claim:
 1. A diamine of the formula ##STR8## wherein X=NH or O and Ris a divalent, substituted or unsubstituted organic group having at themost 20 carbon atoms.
 2. A diamine according to claim 1, wherein R is analkylene group having 2-10 carbon atoms.
 3. A diamine according to claim1, wherein R is a cyclohexylene group or a 1,4-dimethylene cyclohexylenegroup.
 4. A diamine according to claim 1, wherein R is an m- orp-phenylene group.
 5. A diamine according to claim 1, wherein R is thegroup ##STR9## wherein Y is a linear or branched alkylene group having1-4 carbon atoms, --O--, --SO₂ --, ##STR10##
 6. A process for thepreparation of a diamine of the formula ##STR11## wherein X is NH or Oand R is a divalent, substituted or unsubstituted organic group havingat the most 20 carbon atoms, comprising:(a) reacting an acid chloride ofa half ester of terephthalic acid or isophthalic acid with m- orp-nitroaniline to produce a reaction product; (b) reacting said reactionproduct with a bifunctional alcohol of the formula HOROH to produce adinitro compound; (c) reducing said dinitro compound with hydrogen to acorresponding diamine; and (d) isolating said diamine.
 7. A process forthe preparation of a diamine of the formula: ##STR12## wherein X is NHor O and R is a divalent, substituted or unsubstituted organic grouphaving at the most 20 carbon atoms, comprising:(a) reacting an acidchloride of a half ester of terephthalic acid or isophthalic acid withm- or p-nitroaniline to produce a reaction product; (b) hydrolyzing andchlorinating said reaction product in the presence of an acid binder;(c) reacting said hydrolyzed and chlorinated reaction product with abifunctional alcohol of the formula HOROH or a diamine of the formula H₂NRNH₂ to produce a dinitro compound; (d) reducing said dinitro compoundwith hydrogen to a corresponding diamine; and (e) isolating saiddiamine.
 8. A process for the preparation of a dimaine of the formula##STR13## wherein X is NH or O and R is a divalent, substituted orunsubstituted organic group having at the most 20 carbon atoms,comprising:(a) reacting an acid chloride of a half ester of terephthalicacid or isophthalic acid with a bifunctional alcohol of the formulaHOROH or with a diamine of the formula H₂ NRNH₂ in the presence of anacid binder to produce a diester; (b) hydrolyzing said diester to acorresponding diacid; (c) reacting said diacid with m- or p-nitroanilineto produce a dinitro compound; (d) reducing said dinitro compound withhydrogen to a corresponding diamine; and (e) isolating said diamine.